One more thing then I'll shup up..
If the bass EQ and the Avalon's presets are not enough for you, there are possibilities depending on what power amp you have.
Mine, like many, offers no EQ - it just amplifies.
However, my previous power amp, the Crown XTi2000 was much more flexible. As well as hpf, sub and crossover settings, you could plug it into your computer and create up to 25 (IIRC) presets with whatever boost/cut at whatever frequencies you want.
I had a play and created some notch presets (to dial out boom in various rooms) although never needed it.
You could create one and call it "Jazz Rounds" or another called "P Bass Flats"
If you wanted.